Powering Arrays On Or Off; Alternate Path Mode Is Single Mode With Alternate Paths In Standby Only - HP StorageWorks XP12000 User Manual

Figure 8

Alternate path mode is Single mode with alternate paths in Standby only

NOTE:
Figure 8. A notable characteristic of using A/S controller arrays as external storage is that there is
typically only a single port to the owning controller. Paths to the non-owning external controller's
ports are shown as Standby status. I/O load balancing does not occur across external controllers.

Powering arrays on or off

This section describes procedures for powering local and external arrays on or off after External Storage
XP operations have started.
These procedures use the following commands:
• Disconnect Subsystem
Execute the Disconnect Subsystem command from the Command View XP or XP Remote Web Console
GUI when you need to perform maintenance or stop the local or external array. This command stops
acceptance of all host I/O operations to the external LU mapped as the internal LDEV. All outstanding
data in cache memory on the local array intended for the external LU is written (de-staged) to the
external LU.
For instructions on executing the Disconnect Subsystem command, see
or LUs" on page 95.
NOTE:
external LU's mapping, use the Disconnect Volume command and then the Delete LU command. For
instructions, see
• Check Paths & Restore Vol.
External arrays with Active/Standby (A/S) controllers, such as the MSA, are an example of
To disconnect an individual LU, use the Disconnect Volume command. To delete a single
"Deleting external LU mappings (Delete
"Disconnecting external arrays
LU)" on page 101.
External Storage XP user guide 27